Abstract:A signal peptide is a short peptide fused in the recombinant protein N-terminus, generally composed of 15-30 amino acids, guiding the transport of recombinant protein to the periplasmic space of the cell. It is divided into N region, H region and C according to the structure and function. Recombined protein expression in Escherichia coli, often faces with the problem of forming an inclusion body. If the recombined protein is secreted into the periplasmic space, the periplasmic protein can not only help the recombination protein fold into to correct structure but also facilitate the production of disulfide bonds. This paper summarizes the structure composition, action structure and basic secretion pathways of signal peptides; discusses the efficient transport and screening methods of signal peptides. This paper also summarizes the new progress of recombination protein fusion signal peptides in E. coli to achieve perennial expression, and visions the screening techniques of signal peptides in the future.